Display light emitting device

ABSTRACT

When the distance indicated by distance information received by a Bluetooth module ( 31 ) is less than a predetermined first reference distance (KY 1 ), a guidance image ( 33 ) including a distance image ( 33   a ) and a direction image ( 33   b ) is generated, and this guidance image ( 33 ) is displayed on a combiner ( 26 ) of a helmet ( 20 ). By stopping the display of the distance image ( 33   a ) of the guidance image ( 33 ) and continuing to display the direction image ( 33   b ) from when the distance indicated by the distance information becomes less than a second reference distance (KY 2 ) shorter than the first reference distance (KY 1 ) to when the guidance point is reached, the driver&#39;s attention is focused on the direction image ( 33   b ), so that a mistake in the direction of travel at the guidance point can be prevented.

TECHNICAL FIELD

The present invention relates to a display light emitting device thatdisplays a guidance image on a head-up display device of a vehicle, andmore particularly, to a display light emitting device that emits displaylight to display a guidance image on a head-up display device mounted ona helmet.

BACKGROUND ART

Recently, as a display light emitting device that emits display light todisplay a guidance image on a head-up display device of a vehicle, ithas been known to emit display light of a simple display from a displaylight emitting device to a combiner to provide display in order that thedriver is not hindered from making a correct judgment while driving thevehicle. For example, as an example of a display light emitting deviceof a head-up display device, Patent Literature 1 discloses to emitdisplay light so that a display image regarding the distance from thedestination to the own vehicle (distance image) and a display image ofan arrow indicating right and left turn information at the guidancepoint (direction image) are displayed all the time on a head-up displaydevice when the own vehicle reaches a location a first predetermineddistance (300 m) away from the guidance point where the own vehicle mustturn left or right. Moreover, when the own vehicle reaches a locationnearer to the guidance point than the location of the firstpredetermined distance and a second predetermined distance (100 m) awayfrom the guidance point thereafter, the display of the display imageregarding the distance (distance image) and the display image regardingthe driving operation (direction image) is switched from all-the-timedisplay to flashing display.

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Laid-Open Patent Publication No.H08-190696

SUMMARY OF INVENTION Technical Problem

In a head-up display device of a vehicle where limited information isdisplayed, in many cases, a rough value in units of several hundreds ofmeters is measured as the distance to the guidance point and the valueis displayed. On the contrary, according to Patent Literature 1, anarrow and the distance are displayed to provide route guidance. Atlocations far from the guidance point, the distance image is shown by anumerical value and the direction image indicating the direction oftravel is shown by an arrow that is always lit, and at a location nearthe guidance point, the numerical value of the distance image and thearrow of the direction image are both flashed, so that at the locationnear the guidance point, rather the numerical value indicating thedistance attracts the driver's attention and adhering to the numericalvalue, the driver can mistake a wrong point for the guidance point.

The present invention is made in view of the above-described prior art,and an object thereof is to make the driver recognize that the guidancepoint is approaching and at the same time, prevent the guidance displayfrom hindering the driver's correct judgement when a location near theguidance point is reached.

Solution to Problem

To attain the above-mentioned object, according to the presentinvention, when the distance to the guidance point becomes within apredetermined distance, both the distance image and the direction imageare displayed, and when the guidance point becomes nearer, the displayof the direction image up to the guidance point is continued and thedisplay of the distance image is erased.

That is, according to a first aspect of the invention,

a display light emitting device that emits display light to display aguidance image on a combiner mounted on a helmet is provided with;

a wireless communication portion that receives, from a communicationdevice, guidance information including distance information indicativeof a distance to a predetermined guidance point and directioninformation indicative of a direction of travel at the guidance point;and

an image control module having: an image generating portion thatgenerates a guidance image including a distance image indicative of thedistance to the guidance point based on the distance information and adirection image indicative of the direction of travel at the guidancepoint based on the direction information; and an image emitting portionthat emits display light to display the guidance image on the combiner,and controls operations of the image generating portion and the imageemitting portion, and

the image control module

performs control so that, when a condition is satisfied that thedistance indicated by the distance information is less than apredetermined first reference distance, the distance image and thedirection image are generated by the image generating portion anddisplay light to display the guidance image including the generateddistance image and direction image on the combiner is emitted from theimage emitting portion, and

performs control so that from when a condition is satisfied that thedistance indicated by the distance information is less than a secondreference distance shorter than the first reference distance to when theguidance point is reached, the display of the distance image of theguidance image is stopped and display light to continue to display thedirection image is emitted.

According to a second aspect of the invention, in the first aspect ofthe invention,

the image control module

performs control so that until a third reference distance shorter thanthe first reference distance is reached, the direction image generatedby the image generating portion is a first route direction image, and

that when a condition is satisfied that the distance indicated by thedistance information is less than the third reference distance, thedirection image generated by the image generating portion continues tobe emitted from the image emitting portion to the combiner as a secondroute direction image formed of a display image different from the firstroute direction image.

According to a third aspect of the invention, in the second aspect ofthe invention,

the image control module

performs control so that when a condition is satisfied that the distanceindicated by the distance information is less than a fourth referencedistance shorter than the third reference distance, a third routedirection image formed of a display image different from the first routedirection image and the second route direction image is emitted from theimage emitting portion to the combiner.

According to a fourth aspect of the invention, in the third aspect ofthe invention,

the distance from the guidance point to the second reference distance isshorter than the distance from the guidance point to the third referencedistance and is longer than the distance from the guidance point to thefourth reference distance.

According to a fifth aspect of the invention, in any one of the first tofourth aspects of the invention, the first route direction image and thesecond route direction image each include an arrow image, and the arrowimage of the first route direction image and the arrow image of thesecond route direction image are different in display condition.

According to a sixth aspect of the invention, in the third or the fourthaspect of the invention, the first route direction image, the secondroute direction image and the third route direction image each includean arrow image, and the arrow images of the first route direction image,the second route direction image and the third route direction image aredifferent in display condition.

According to a seventh aspect of the invention, in any one of the firstto sixth aspects of the invention, the distance interval from thelocation of the second reference distance to the guidance point isshorter than the distance interval from the location of the firstreference distance to the location of the second reference distance.

According to an eighth aspect of the invention, in any one of the firstto seventh aspects of the invention, a fifth reference distance is setthat is from the guidance point to a location further away from theguidance point than the location of the first reference distance,

the fifth reference distance is set at a plurality of points everydistance interval longer than the first reference distance, and

the image control module performs control so that the guidance imageincluding the distance image and the direction image is displayed for aset predetermined period of time when each fifth reference distance isreached.

According to a ninth aspect of the invention, in the eighth aspect ofthe invention, the display time of the guidance image displayed when thefifth reference distance is reached is not more than 30 seconds.

Advantageous Effects of Invention

According to the first aspect of the invention, when the distance to theguidance point becomes the first reference distance, the distance imageand the direction image are displayed, and when the distance to theguidance point becomes the second reference distance, the display of thedistance image is stopped and the display of the direction image iscontinued until the guidance point is reached; for this reason, not onlythe driver can strongly recognize that the guidance point is approachingbut also the distance image can be prevented from obstructing a correctjudgement by the driver.

According to the second aspect of the invention, when the distance tothe guidance point becomes less than the third reference distance, thesecond route direction image different from the first route directionimage is displayed on the combiner; for this reason, not only thedriver's attention is focused on the change of the direction image butalso the second route direction image is changed so as to be conspicuousin order that the driver can focus attention thereon, so that the drivercan be prevented from mistaking a wrong direction for the direction oftravel at the guidance point.

According to the third aspect of the invention, when the distance to theguidance point becomes less than the fourth reference distance shorterthan the third reference distance, the third route direction imagedifferent from the first route direction image and the second routedirection image is displayed on the combiner; for this reason, thedriver can focus attention only on the third route direction image, sothat the driver can be surely prevented from mistaking a wrong directionfor the direction of travel at the guidance point.

According to the fourth aspect of the invention, since the secondreference distance is a distance between the third reference distanceand the fourth reference distance, after the distance becomes less thanthe third reference distance and the display is changed from the firstroute direction image to the second route direction image to therebyerase the distance image and attention is focused only on the directionimage, the display is changed from the second route direction image tothe third route direction image after a little bit of traveling with thedistance image erased. Consequently, not only the driver can recognizethat the guidance point is near but also the guidance image where thedistance image is erased makes the direction of travel verycomprehensible.

According to the fifth aspect of the invention, at the time oftraveling, in the display condition of the arrow image, a change occurssuch as a change of the color of the arrow, a change of the flashingcondition of the arrow, a change of the thickness of the arrow and acombination thereof, so that the arrow can be made more noticeable tothe driver's eyes.

According to the sixth aspect of the invention, since the displaycondition of the arrow image is changed in two steps at the time oftraveling, the change of the arrow is surely burned into the driver'seyes. In particular, since switching to the second route direction imageis made after the distance image is erased from the first routedirection image where both the direction image and the distance imageare displayed, the driver not only can easily recognize that theguidance point is approaching but also can surely grasp the direction oftravel.

According to the seventh aspect of the invention, since the distanceinterval from the location of the second reference distance to theguidance point is shorter than the distance interval from the locationof the first reference distance to the location of the second referencedistance at the time of traveling, the time during which the distanceimage in the guidance image is not displayed is short. Consequently, thepossibility decreases that the driver loses sight of or mistakes theguidance point, so that the driver can pass the guidance point withoutgetting lost according to the direction image displayed in the guidanceimage.

According to the eighth aspect of the invention, since at the fifthreference directions set at locations ahead of the location of the firstreference distance at the time of traveling, for example, display isprovided in the guidance image for a short period of time every turningpoint value as a rough indication of each distance, the driver becomesaware that the guidance point is gradually approaching whileunderstanding that the direction of travel is correct without thetraveling being hindered, so that the driver can drive the vehicle atease.

According to the ninth aspect of the invention, since the guidance imageis displayed only a little at each turning point value as the roughindication of the distance, the driver can drive concentratedly whileobtaining necessary information.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing the structure of a navigation system providedwith a display light emitting device according to a first embodiment ofthe present invention.

FIG. 2 is a functional block diagram showing the structure of thenavigation system provided with the display light emitting deviceaccording to the first embodiment of the present invention.

FIG. 3 is a flowchart showing the processing performed by amicrocomputer of a smartphone when a car navigation application isexecuted.

FIG. 4 is a view showing an image displayed on a touch panel of thesmartphone during a guidance operation.

FIG. 5 is a flowchart showing an operation of a stationary stateexecuted by the display light emitting device according to the firstembodiment of the present invention.

FIG. 6 is a view showing, in time series, when each of the displaycontents of a guidance image outputted by an image output portion of thedisplay light emitting device is displayed until a guidance point isreached.

FIG. 7 is a view showing an example of the guidance image outputted bythe image output portion of the display light emitting device accordingto the first embodiment of the present invention.

FIG. 8 is a view showing an example of the guidance image outputted bythe image output portion of the display light emitting device accordingto the first embodiment of the present invention.

FIG. 9 is a view showing an example of the guidance image outputted bythe image output portion of the display light emitting device accordingto the first embodiment of the present invention.

FIG. 10 is a view showing an example of the guidance image outputted bythe image output portion of the display light emitting device accordingto the first embodiment of the present invention.

FIG. 11 is a view showing a guidance image outputted by the image outputportion of a display light emitting device according to a secondembodiment of the present invention.

FIG. 12 is a view showing a guidance image outputted by the image outputportion of a display light emitting device according to a thirdembodiment of the present invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of the present invention will bedescribed based on the drawings.

FIG. 1 is a view showing the structure of a navigation system which isan example where the present invention is applied to a motorcycle. FIG.2 is a functional block diagram showing the structure of the navigationsystem provided with a display light emitting device according to thefirst embodiment of the present invention. As shown in FIG. 1 , thisnavigation system 1 is provided with a smartphone 10 as a communicationdevice and a helmet 20 of the motorcycle. The navigation system 1 isalso employable for vehicles other than motorcycles such as jet skis,bicycles and snowmobiles (snow bikes). The smartphone 10 may bedetachably attached to the motorcycle or may be accommodated in a bag orthe like capable of receiving GPS signals.

As shown in FIG. 2 , the smartphone 10 is provided with: a LAN interface11 that performs wireless communications using Bluetooth (trademark); aGPS receiver 12; a WAN interface 13 that transmits and receives audiosignals through a mobile-phone line; a microcomputer 14 as a signalprocessor; and a touch panel 15 as an input portion. The microcomputer14 is provided with: a mobile operating system 14 a as the OS of thesmartphone 10; a car navigation service application (hereinafter,referred to as “car navigation application”) 14 b that runs on themobile operating system 14 a by using location information obtained bythe GPS receiver 12 and the like. The smartphone 10 is structured so asto be capable of automatically searching for a route from the currentlocation to the destination based on the location information (currentlocation information) obtained by the GPS receiver 12 and thedestination information inputted on the touch panel 15 and making routesetting by using the microcomputer 14. The car navigation application 14b is structured so as to calculate the distance from the currentlocation to the next guidance point and the time to when the nextguidance point is reached from the current location, based on mapinformation and current location information. On the touch panel 15,guidance information up to a predetermined guidance point is displayed.Although concrete examples of the guidance information display will bedescribed later in detail, for example, distance information indicativeof the distance to the guidance point and direction informationindicative of the direction of travel at the guidance point aredisplayed.

As shown in FIG. 1 , in the center on the front surface of the helmet20, a window hole 21 is formed that has a substantially rectangularshape extending in the horizontal direction. The helmet 20 is providedwith a shield 22 having translucency and being substantially U-shaped inplan view. Both end portions of the window hole 21 are pivotallysupported by the side wall portions of the helmet 20, respectively, andmove rotationally in the vertical direction, thereby opening and closingthe window hole 21. A plurality of switches including a first switch 23and a second switch 24 are disposed on the left side of the window hole21 on the outer surface of the helmet 20 when viewed from the helmetwearer, that is, in a position corresponding to an ear of the helmetwearer. The first switch 23 activates a display light emitting device 30(described later) of a head-up display device 40 by being long-pressed.The first switch 23 forcibly stops the display light emitting device 30by being short-pressed. The second switch 24 is a switch of multiplefunctions including telephone incoming and telephone conversation.

Moreover, a position to the right of the center in the horizontaldirection when viewed from the helmet wearer on the upper edge of thewindow hole 21 of the helmet 20, a plate-like semi-transparent combiner26 is attached from the inside of the helmet 20 through an attachmentmember 27. The display light emitting device 30 according to theembodiment of the present invention and a mirror 28 that projects to thecombiner 26 the display light emitted by the display light emittingdevice 30 are incorporated below the window hole 21 of the helmet 20.The display light emitting device 30, the combiner 26 and the mirror 28constitute the head-up display device 40.

As shown in FIG. 2 , the display light emitting device 30 is providedwith: a Bluetooth module 31 (wireless communication portion) capable ofcommunicating with the smartphone 10 by using Bluetooth; and an imagecontrol module 32 that generates a guidance image to be displayed on thecombiner 26 based on the information received by the Bluetooth module 31and emits display light to display the generated guidance image on thecombiner 26.

The Bluetooth module 31 receives, from the LAN interface 11 of thesmartphone 10, guidance information such as information on the route toa set guidance point, distance information indicative of the distance tothe set guidance point, direction information indicative of thedirection of travel at the guidance point, speed information indicativeof the current speed and the time required to reach the guidance point.

The image control module 32 is provided with: a microcomputer 32 a thatreceives, from the Bluetooth module 31, the guidance informationreceived from the LAN interface 11 and generates a guidance image 33from the received guidance information; a flash ROM (Read Only Memory)32 b that stores images and the like; a GDC (Graphic Display Controller)32 c (image generating portion); and an LCOS (Liquid Crystal on Silicon)32 d (image emitting portion) that emits display light to display thegenerated image on the combiner 26.

In accordance with an instruction from the microcomputer 32 a, the imagecontrol module 32 controls the GDC 32 c so as to generate the guidanceimage 33 by combining the guidance information such as the distanceinformation and the direction information received from the Bluetoothmodule 31, images stored in the flash ROM 32 b and the like, andcontrols the LCOS 32 d so as to emit display light corresponding to thegenerated guidance image 33. In the guidance image 33, for example, asshown in FIG. 7 , a distance image 33 a on the distance to the guidancepoint is displayed by a numerical value in the upper right part, and adirection image 33 b indicative of the direction of travel at theguidance point is displayed by an arrow in the upper left part.Moreover, in the guidance image 33, a time image 33 c indicative of thetime required to reach the guidance point is displayed by minutes andseconds in the lower right part, and a time-of-day image 33 d as anestimated arrival time is displayed by a clock diagram in the lower leftpart. The distance image 33 a is displayed in the unit of “km” when thedistance to the guidance point is long, and is displayed in the unit of“m” when the distance to the guidance point is less than 1 km.

The LCOS 32 d emits display light to display the guidance image 33generated by the GDC 32 c on the combiner 26. The output of the guidanceimage 33 by the LCOS 32 d can be forcibly stopped by the first switch 23being short-pressed.

In the navigation system 1 structured as described above, the processingshown in the flowchart of FIG. 3 is performed by the microcomputer 14 ofthe smartphone 10 executing the car navigation application 14 b.

First, at step S001, a screen to prompt the user to set a destination isdisplayed on the touch panel 15.

Then, at step S002, when an input operation to set a destination by theuser is performed on the touch panel 15, the set destination is storedas the destination of the guidance object.

Then, at step S003, the guidance route from the point of departure tothe destination of the guidance object stored at step S002 is searchedfor, and the guidance route obtained by the search is stored.

Thereafter, at step S004, a guidance operation is executed in accordancewith the guidance route stored at step S003. The microcomputer 14 duringthe guidance operation obtains, every second, the distance informationindicative of the distance to a predetermined guidance point such as thenext intersection and the direction information indicative of thedirection of travel at the guidance point according to the guidanceroute obtained by the search using the GPS receiver 12. Then, based onthe obtained distance information and direction information, the maparound the current location, the distance to the guidance point, thedirection of travel at the guidance point and the like are outputted anddisplayed on the touch panel 15 as the guidance information. FIG. 4shows an example of the image displayed on the touch panel 15 during theguidance operation. In FIG. 4, 16 a is an activation switch of thesmartphone, 16 b is the map around the current location, 16 c is thedistance to the guidance point, and 16 d is the direction of travel atthe guidance point. Moreover, during the guidance operation, themicrocomputer 14 transmits (outputs) the distance information and thedirection information obtained by the execution of the car navigationapplication 14 b, as the guidance information by wireless communicationthrough the LAN interface 11.

During the guidance operation, at step S005, when an input operation toend the car navigation application 14 b by the user is performed on thesmartphone 10, the microcomputer 14 ends the guidance operation.

Hereinafter, an operation of the navigation system 1 structured asdescribed above will be described based on FIGS. 5 to 10 . In thefollowing, a case where the navigation system 1 is activated at alocation where a motorcycle is not less the 5 km away will be describedas an example.

First, when the driver of a motorcycle or the like wears the helmet 20and long-presses the first switch 23 while carrying the smartphone 10where the car navigation application 14 b is running, the display lightemitting device 30 is activated. The smartphone 10 where the carnavigation application 14 b is running transmits the distanceinformation and the direction information updated every second, bywireless communication by the LAN interface 11 as the guidanceinformation up to the guidance point such as the next intersection.After activated, the display light emitting device 30 repetitivelyexecutes a stationary operation while the wireless communication withthe smartphone 10 is connected by the Bluetooth module 31.

In the stationary operation, it is determined whether the motorcyclethat the driver is driving reaches a predetermined turning point value(fifth reference distance KY5) or not, and when the motorcycle reachesthe predetermined turning point value, the guidance image 33 isdisplayed to notify the driver that the guidance route is correct andthat the motorcycle is gradually approaching the guidance point.Specifically, when the distance D from the current location to theguidance point is more than 5 km, it is determined that the motorcycleis considerably away from the guidance point and the display of theguidance image 33 of the stationary operation is omitted, whereas whenthe motorcycle reaches the turning point value, that is, 5 km, theguidance image 33 is displayed for a short period of time (for example,10 seconds). Then, after the guidance image 33 is displayed for 10seconds, the display of the guidance image 33 is stopped. As theguidance image 33, for example as shown in FIG. 7 , the direction oftravel, the distance to the guidance point, the estimated time ofarrival and the like are displayed. Such short-time display of theguidance image 33 is repeated also when the motorcycle reaches otherturning point values (fifth reference distances KY5) 4 km, 3 km, 2 kmand 1 km. This display enables the driver to recognize that the guidanceroute is correct and that the motorcycle reaches the turning point valueof a predetermined distance and is gradually approaching the guidancepoint. For example, when running at an average speed of 36 km per hourin an urban area, the motorcycle travels 100 m for ten seconds, and whenthe motorcycle reaches a turning point value such as 5 km, the guidanceimage 33 is displayed only while the motorcycle is running a distance of100 m. Moreover, for example, in a case where an interchange is theguidance point when the motorcycle is running on an express way, themotorcycle travels 200 m for ten seconds when running at an averagespeed of 72 km per hour, and when the motorcycle reaches a turning pointvalue such as 5 km, the guidance image 33 is displayed while themotorcycle is running a succeeding distance of 200 m. Then, for example,when the location of a first reference distance KY1 as the turning pointvalue where the distance to the guidance point is 500 m is reached, theguidance image 33 is displayed all the time to provide stationarydisplay that makes the driver recognize that the guidance point isapproaching and that can surely guide the driver to the guidance point.

This stationary operation will be described in detail based on theflowchart of FIG. 5 .

First, by the first switch 23 being long-pressed, the display lightemitting device 30 of the head-up display device 40 is activated, andthe process proceeds to step S101. At this step S101, a count value k isinitialized to 1 by the microcomputer 32 a of the image control module32, and the process proceeds to step S102. The count value is set merelyfor the sake of convenience.

Then, at step S102, the Bluetooth module 31 receives the distanceinformation updated and transmitted every second from the smartphone 10where the car navigation application 14 b is running, and the processproceeds to step S103.

At step S103, the microcomputer 32 a of the image control module 32determines whether a distance condition that a distance D indicated bythe distance information received by the Bluetooth module 31 (thedistance to the guidance point) is less than a predetermined referencedistance R_(k) is satisfied or not. Here, the count value k starts withk=1 when this display light emitting device 30 is activated, andsuccessively becomes k+1, and as the count value k becomes k=1, 2, 3, 4,5 and 6, R_(k) successively becomes R₁ to R₆. In the first embodiment ofthe present invention, R₁ to R₆ are set as follows: R₁=5 km, R₂=4 km,R₃=3 km, R₄=2 km, R₅=1 km, and R₆=500 m.

When the result of the determination is NO at S103, since it is a casewhere the distance condition that the distance from the current locationto the guidance point is less than the reference distance R_(k) is notsatisfied, the process proceeds to step S104. That is, since the countvalue k=1 at first and R_(k)=R₁=5 km, it is determined whether thedistance D is D≤5 km (fifth reference distance KY5) or not. Since thecurrent location of travel (D>5 km) is not less than 5 km away from theguidance point and the distance condition (D≤5 km) is not satisfied, theprocess proceeds to step S104 where the next reception is waited for andthe display of the guidance image 33 of the stationary operation is notexecuted.

At step S104, since the current location of travel is not less than 5 kmaway from the guidance point, the display of the guidance image 33 ofthe stationary operation is omitted, and the process waits until thedistance information and the direction information transmitted by thesmartphone 10 are newly received by the Bluetooth module 31 and returnsto step S102. That is, since the distance D during traveling is not lessthan 5 km, the process proceeds from step S104 to S102 and thedetermination at step S103 is repeated until the distance informationupdated every second becomes not more than 5 km.

On the other hand, when the location of travel updated every secondbecomes D≤5 km, since the distance condition is satisfied, thedetermination result is YES at step S103, and the process proceeds tostep S105. At step S105, the microcomputer 32 a determines whether thecount value k is 6 or not. When the count value k is not 6, thedetermination result is NO, and the process proceeds to step S106. Onthe other hand, when the count value k is 6, the determination result isYES, and the process proceeds to step S109. That is, k=6 is D6=500 m,and it is determined whether or not the location of the distance D isnot more than 500 m (first reference distance KYT) which is a distancenear the guidance point. When it is not more than 500 m, thedetermination result is YES, and the process proceeds to step S109 wheredetermining that a distance near the guidance point is reached, thedisplay of the guidance image 33 is performed. On the other hand, whenthe location of the distance D is not less than 500 mm away from theguidance point, the determination result is NO, and the process proceedsto step S106 where another guidance image 33 indicating that a distancenear the guidance point is not reached is displayed.

At step S106, the microcomputer 32 a determines whether the distance DR_(k+1) is satisfied or not. When the distance D R_(k+1) is notsatisfied, the determination result is NO, and the process proceeds tostep S107. On the other hand, when it is satisfied, the determinationresult is YES, and the process proceeds to step S108. That is, in theabove-described case, since the count value k=1, R_(k+1)=R₂=4 km, and itis determined whether the distance D to the guidance point satisfies thedistance condition that D≤4 km (fifth reference distance KY5) or not.Although D<5 km at the location of travel at this time and the distanceis updated every second, since the microcomputer 32 a makes thedetermination within a short period of time of several microseconds, itcan be said that the distance D at the current location of travel isbetween 5 km and 4 km. Therefore, since the distance D≤R₂ (4 km) is notsatisfied, the determination result is NO, and the process proceeds tostep S107.

At step S107, the LCOS 32 d continues to emit display light to displaythe guidance image 33 on the combiner 26 for ten seconds. In theguidance image 33, as shown in FIGS. 6 and 7 , the numerical value ofthe distance image 33 a, the arrow of the direction image 33 b of thedirection of travel, the time image 33 c (time required to arrive) andthe time-of-day image 33 d (estimated time of arrival) are displayed.The value of 5 km as the distance image 33 a, the right-turn arrow asthe direction image 33 b, six minutes as the required time of the timeimage 33 c and ten o'clock as the estimated time of arrival of thetime-of-day image 33 d shown in FIG. 7 are merely samples and are notthe actual numerical values and required time. Moreover, as shown inFIG. 6 , an announcement “About 5 km ahead, in the direction of . . . ”is provided by voice guidance. At this location of travel, since thedistance D to the guidance point is not not more than 500 m and it isunnecessary to display the guidance image 33 all the time, the guidanceimage 33 is displayed only for a short period of time. While thisguidance image 33 is displayed, the GDC 32 c of the image control module32 generates the guidance image 33 by combining with the information ofthe flash ROM 32 b in accordance with an instruction from themicrocomputer 32 a, and the LCOS 32 d emits display light to display theguidance image 33 generated by the GDC 32 c on the combiner 26. Sincethe distance received by the Bluetooth module 31 is updated everysecond, the numerical value of the distance image 33 a of the generatedguidance image 33 is also updated every second. Moreover, not only thenumerical value of the distance image 33 a of the guidance image 33 butalso the display of the time image 33 c and the display of the clockdiagram of the time-of-day image 33 d are also updated every second.Then, when ten seconds have elapsed since the start of the display lightemission by the LCOS 32 d, the display light emission by the LCOS 32 dis ended, and the process proceeds to step S108.

At step S108, after the microcomputer 32 a adds 1 to the count value kto make the count value k=2, the process returns to step S102.

Then, at step S102, anew distance D is received. Thereafter, whether ornot the new distance D obtained at step S102 is not more than R₂, thatis, not more than R₂=4 km (fifth reference distance KY5) is determinedat step S103. Under a condition where it is not not more than 4 km, thedetermination result is NO, and the process is returned to S102 withoutthe emission of the display light. Under this condition, since displaylight is not emitted, the guidance image 33 is not displayed, either.Since the distance D at the current location of travel is between 5 kmand 4 km and the distance D is updated every second, the motorcycle runswithout the guidance image 33 displayed until the display condition ofthe guidance image 33 is satisfied.

Then, when the distance D updated every second becomes D≤4 km, since itis determined at step S103 that the distance D is not more than 4 km,the process proceeds to step S107 through steps S105 and step S106, andthe guidance image 33 in accordance with the distance at that time isdisplayed for ten seconds. Thereafter, the process proceeds to stepS108, the count value becomes k=3, and the process returns to step S102.

In this manner, short-time display of the guidance image 33 as describedabove is repeated when R_(k) becomes R₃, R₄ and R₅. That is, when R_(k)becomes R₃=3 km (fifth reference distance KY5), R₄=2 km (fifth referencedistance KY5) and R₅=1 km, for example, the guidance image 33 as shownin FIG. 6 is displayed for ten seconds. When the process proceeds tostep S108 after the guidance image 33 is displayed for ten seconds everytime the location where R₅=1 km is passed, k=k+1, that is, k=6 andR_(k)=R₆=500 m. Then, the process returns to step S102.

Thereafter, the process proceeds from step S102 to step S103, and it isdetermined whether or not the distance D to the guidance point is notmore than 500 m (first reference distance KYT) that is a distance nearthe guidance point. When the distance D becomes not more than 500 m,since the determination result is YES and D R_(k) (R_(k)=R₆=500 m) issatisfied at step S103, the process proceeds to step S105. At step S205,whether k=6 or not is determined. Since k=6 under this runningcondition, the determination result is YES, and the process proceeds tostep S109.

At step S109, display as a distance near the guidance point is provided.That is, the process proceeds to step S109 and display light to displaythe guidance image 33 on the combiner 26 continues to be emitted untilD=0 km (guidance point). At this time, the GDC 32 c generates theguidance image 33 in accordance with an instruction from themicrocomputer 32 a, and the LCOS 32 d emits display light to display theguidance image 33 generated by the GDC 32 c on the combiner 26.Specifically, as shown in FIGS. 6 and 7 , in the guidance image 33, thedistance image 33 a to the guidance point is displayed by a blacknumerical value on the right side in the upper row, and the directionimage 33 b at the guidance point is displayed by a blue arrow on theleft side in the upper row. The display image of this direction image 33b will be referred to as first route direction image 33 b 1. Moreover,in the guidance image 33, the time image 33 c as the time required toreach the guidance point is displayed by black numerical value on theright side in the lower row, and the clock diagram of the time-of-dayimage 33 d as the estimated time of arrival is displayed in black on theleft side in the lower row. The guidance image 33 when the firstreference distance KY1 is reached is the same as the guidance image 33displayed for ten seconds when each fifth reference distance KY5 isreached, and is different in that it is displayed all the time.Moreover, since the distance received by the Bluetooth module 31 isupdated every second, the generated guidance image 33 is also updatedevery second. That is, the numerical value of the distance image 33 a isupdated every second. Then, the process proceeds to step S110.

At step S110, it is determined whether the distance D indicated by thedistance information received by the Bluetooth module 31 is not morethan 200 mm (third reference distance KY3) or not. When the distance Dis not not more than 200 m at step S109, the determination result is NO,and the process returns to step S109. On the other hand, when thedistance D becomes not more than 200 mm, the determination result isYES, and the process proceeds to step S111.

At step S111, as shown in FIGS. 6 and 8 , the first route directionimage 33 b 1 which is the display image of the blue arrow of theguidance image 33 is changed to a second route direction image 33 b 2which is the display image of a yellow arrow, thereby inviting thedriver's attention in the direction of travel, and the process proceedsto step S112.

At step S112, it is determined whether the distance D indicated by thedistance information received by the Bluetooth module 31 is not morethan 150 m (second reference distance KY2) or not. When the distance Dis not not more than 150 mat step S112, the determination result is NO,and the process returns to step S111. On the other hand, when thedistance D becomes not more than 150 m, the determination result is YES,and the process proceeds to step S113.

At step S113, as shown in FIGS. 6 and 9 , the numerical display of thedistance image 33 a of the guidance image 33 is erased so as not to bedisplayed. By doing this, the driver is made to recognize that it ishardly worth displaying the distance in the guidance image 33 becausethe distance D to the guidance point is considerably near, and thedisplay of the direction of travel in the guidance image 33 is madeconspicuous; thereafter, the process proceeds to step S114. While thetime image 33 c and the time-of-day image 33 d in the guidance image 33are displayed as they are in the guidance image 33 at this time, thesedisplays may also be erased.

At step S114, it is determined whether the distance D indicated by thedistance information received by the Bluetooth module 31 is not morethan 70 m (fourth reference distance KY4) or not. When the distance D isnot not more than 70 mat step S114, the determination result is NO, andthe process returns to step S113. On the other hand, when the distance Dbecomes not more than 70 m, the determination result is YES, and theprocess proceeds to step S115.

At step S115, as shown in FIGS. 6 and 10 , under a condition where thenumerical display of the distance image 33 a in the guidance image 33 iserased, the display image of the yellow arrow of the second routedirection image 33 b 2 is changed to a third route direction image 33 b3 formed of a display image of a red arrow, thereby further inviting thedriver's attention to the direction of travel, and the process proceedsto step S116. While the time image 33 c and the time-of-day image 33 din the guidance image 33 are displayed as they are in the guidance image33 at this time, these displays may also be erased.

At step S116, it is determined whether the distance D indicated by thedistance information received by the Bluetooth module 31 is 0 m or not.When the distance D is not 0 mat step S116, the determination result isNO, and the process returns to step S115. On the other hand, when thedistance D becomes 0 m, the determination result is YES, and all thedisplay light emitted from the LCOS 32 d is turned off and the displayof the guidance image 33 in the stationary condition is ended. After theend of these stationary operations, the guidance point is switched, andthe next stationary operations are continuously performed.

As described above, according to the first embodiment, when the distanceD to the guidance point becomes near the guidance point, the displaycolor of the travel direction of the direction image 33 b issuccessively changed, for example, from blue to yellow and from yellowto red so as to be conspicuous, so that the driver's attention isattracted more to the direction of travel than to the distanceinformation. When the location at a distance near the guidance point isreached, the display of the distance image 33 a is stopped and thedisplay of the direction image 33 b is continued, so that not only thedriver can strongly recognize that the guidance point is approaching butalso the distance image 33 a can be prevented from obstructing a correctjudgement by the driver.

In particular, in the first embodiment, since the display image color ofthe arrow of 200 m (third reference distance KY3) is changed from blueto yellow and the distance display is stopped at the point of 150 m(second reference distance KY2) after this color change, the driver'sattention is more strongly focused on the direction of travel.Thereafter, since the display image color of the arrow of the directionimage 33 b is changed from yellow to red at the point of 70 m (fourthreference distance KY4), the driver's attention is further focused onthe direction of travel, so that the motorcycle can travel according tothe guidance without mistaking a wrong direction for the direction oftravel at the guidance point. In particular, since the navigation systemis such that the numerical value itself of the distance is indicated bya rough numerical value in units of several hundreds of meters, if thedistance image 33 a is displayed adhering to numerical values of shortdistances, there is a possibility that the motorcycle runs with thedistance to the guidance point not coinciding with the distancedisplayed in the distance image 33 a. Therefore, in the firstembodiment, by daring to erase the display of the distance numericalvalue when the distance (150 m=the second reference distance KY2) nearthe guidance point is reached, the driver can drive with attentionfocused on the direction image 33 b without adhering to the distancenumerical value.

While in the above description of the stationary operation, a case inwhich the navigation system 1 is activated at a location where themotorcycle is not less than 5 km away from the guidance point isdescribed as an example, the display light emitting device 30 operatesaccording to the flowchart shown in FIG. 5 also when the navigationsystem 1 is activated at a location where the motorcycle is less than 5km away from the guidance point. A case in which the navigation system 1is activated, for example, at a location where the motorcycle is 3.4 kmaway from the guidance point will be described as an example. Regardingsteps similar to the above-described ones, brief description will begiven.

When the first switch 23 is long-pressed at a location where themotorcycle is 3.4 km away from the guidance point, the display lightemitting device 30 of the head-up display device 40 is activated, and atstep S101, the count value k is initialized to 1 by the microcomputer 32a.

Then, at step S102, the Bluetooth module 31 receives the distanceinformation updated and transmitted every second from the smartphone 10where the car navigation application 14 b is running, and the processproceeds to step S103.

At step S103, whether a distance condition that the distance D≤R₁ (R₁=5km) is satisfied or not is determined. Since D=3.4 km, determining thatthe display condition is satisfied, the process proceeds to step S105.

At step S105, whether the count value k is k=6 or not is determined.Since the count value k is k=1, the process proceeds to step S106.

At step S106, whether the distance D≤R_(k+1) (R_(k+1)=R₂=4 km) issatisfied or not is determined. Since the distance D=3.4 km and D≤4 kmis satisfied, the process proceeds to step S108.

At step S108, after the microcomputer 32 a adds 1 to the count value kto thereby make the count value k=2, the process returns to S102.

Then, when a new distance D is received at step S102, whether thedistance D is not more than R₂, that is, not more than R_(k)=R₂=4 km ornot is determined at step S103. Since the current point is a locationwhere D=3.4 km, determining that the determination condition issatisfied, the process proceeds to step S105.

At step S105, whether the count value k is k=6 or not is determined. Atthis time, since the count value k is k=2 and not k=6, determining thatthe determination condition is not satisfied, the process proceeds tostep S106.

At step S106, whether D≤R_(k+1) is satisfied or not is determined. SinceR_(k+1)=R₃=3 km and the current distance D is D=3.4 km, thedetermination condition D(3.4 km)≤R₃(3 km) is not satisfied. Therefore,the process proceeds to step S107. The steps above are executed inseveral milliseconds.

At step S107, a guidance image 33 at a location where the current pointis D=3.4 km is generated by the image control module 32, and displaylight of the guidance image 33 is emitted by the LCOS 32 d and displayedon the combiner 26 for ten seconds. Then, after ten seconds have elapsedsince the start of the display light emission, the LCOS 32 d ends thedisplay light emission, and the process proceeds to step S108.

At step S108, the count value k is made k=3, and the process returns tostep S102. In this way, when R_(k) successively becomes R₃, R₄ and R₅and the current point becomes 3 km, 2 km and 1 km, the ten-seconddisplay of each guidance image 33 is performed. Then, when R_(k) becomesR₆ and the current point becomes a location 500 m away from the guidancepoint, the all-time display of the guidance image 33 is performed.

As described above, when the current location is at a point 3.4 km awayfrom the guidance point, the operation is executed until the count valuek becomes from k=1 to k=2 according to the flow chart shown in FIG. 5 toidentify the current location, the ten-second display of the guidanceimage 33 is executed at this point, and thereafter, the ten-seconddisplay of the guidance image 33 is repeated at the points of 3 km, 2 kmand 1 km. Thereafter, when R_(k) becomes R₆ and the current location isa location 500 m away from the guidance point, the all-time display ofthe guidance image 33 is executed.

Moreover, when the first switch 23 is long-pressed at a location wherethe motorcycle is 0.4 km away from the guidance point, the display lightemitting device 30 of the head-up display device 40 is activated. Afterthe count value k is initialized to 1 at step S101, steps as describedabove are repeated until the count value k successively becomes from k=1to k=6. When k=6 after the determination is made at step S105, theprocess proceeds to step S109, and the above-described display operationfor when the guidance point is approaching is executed. That is, thedisplay of the guidance image 33 at a location near the guidance pointis executed without the ten-second display of the guidance image 33being executed.

As described above, in the flowchart shown in FIG. 5 , in a case wherethe navigation system 1 is activated and the stationary operation isperformed, for example, when the navigation system 1 is actuated at alocation not less than 5 km away from the guidance point, the guidanceimage 33 is displayed for ten seconds at locations 5 km, 4 km, 3 km, 2km and 1 km away from the guidance point, and the location not more than500 m away from the guidance point is reached, the guidance image 33 isdisplayed all the time. Moreover, when the navigation system 1 isactivated at a location nearer to the guidance point than the location 5km away from the guidance point, since whether the current location isbetween R_(k) and R_(k+1) or the count value k=6 or not is immediatelydetermined, the current location can be instantaneously grasped and thenecessary steps can be executed. That is, when the navigation system 1is activated, by executing the flow to successively increase the countvalue k by one from 1, the current location of the driver can beinstantaneously identified and the necessary steps can be executed atany location.

In particular, when the distance to the guidance point becomes a neardistance of not more than 500 mm (first reference distance KY1), theguidance image 33 is displayed all the time to provide guidance, and ata location extremely near the guidance point (second reference distanceKY2), for example, at a location 150 m away from the guidance point, thedisplay of the distance image 33 a of the guidance image 33 is stoppedand guidance is provided only by the direction image 33 b, so that thedriver can drive on a correct route according to the directioninformation without influenced by the distance information at a locationextremely near the guidance point.

In common navigation systems, since the guidance point of the vehicle ismeasured and displayed by a rough value of approximately severalhundreds of meters, the numerical value of the distance can be incorrectat an extremely near location within several hundreds of meters from theguidance point. On the contrary, according to the present invention,since the distance image 33 a as the distance information is erased whena location extremely near the guidance point is reached as describedabove, the driver is never misled by the distance image 33 a when guidedto the guidance point by the guidance image 33. In that case, since thedriver's attention is further paid on the direction image 33 b bychanging the display condition of the direction image 33 b so as to beconspicuous, the driver's attention to the direction image 33 bincreases, so that the driver can surely drive to the guidance pointaccording to the direction information.

It is preferable that the second reference distance as the distance to alocation extremely near the guidance point be approximately 100 to 200m.

Second Embodiment

A second embodiment will be described based on FIG. 11 . The secondembodiment is different from the first embodiment in that the distanceinformation of the guidance image 33 shown when the driver reaches thefourth reference distance (70 m) is changed, and is the same as thefirst embodiment except for this.

That is, as shown in FIG. 11 , the direction image 33 b of the guidanceimage 33 is displayed in a similar manner to the direction image 33 b ofthe first embodiment, and an easy-to-understand display is provided by acharacter image 33 e “Turn right at the next traffic light, in thedirection of . . . ” indicating the direction of travel at the guidancepoint by characters. At this time, the time image is erased togetherwith the distance information.

In this second embodiment, since information on the intersection at theguidance point is displayed in the guidance image 33 in detail and in aneasy-to-understand manner, the driver can be made less likely to make amistake in the direction of travel at the guidance point.

Third Embodiment

A third embodiment will be described based on FIG. 12 . The thirdembodiment is different from the first embodiment in that the guidanceimage 33 displayed when the driver reaches the fourth reference distance(70 m) is changed, and is the same as the first embodiment except forthis.

That is, in the third embodiment, for example, as shown in FIG. 12 , aphrase “in the direction of . . . ” which is an explanation by voice isdisplayed also by a character image 33 f as it is in the guidance image33 so as to be easy-to-understand. Further, in the lower row of theguidance image 33, the arrow of a direction image 33 g and the numericalvalue of a distance image 33 h at the guidance point next to thecurrently explained guidance point are displayed next to each other. Byadding these pieces of information at the next guidance point to theguidance image 33, the information on the next guidance point becomesclear, so that the driver can drive at ease. In particular, how muchdistance there is to the next guidance point or in which direction thenext guidance point is can be easily understand, so that the driver candrive without making a mistake in the direction of travel. As describedabove, in a case where the next guidance point is near the currentlyexplained guidance point and information on the next guidance point isimmediately required, for example, during driving in a labyrinthineurban area, when the intersection as the guidance point explained nextto the currently explained guidance point is located at a near distancesuch as 50 m or 100 m from the currently explained guidance point, thedriver can drive without making a mistake in the direction of travel.

OTHER EMBODIMENTS

Moreover, in the above-described first to third embodiments, the LCOS 32d may emit display light in such a manner that the guidance image 33 isfaded in when the display of the guidance image 33 by the stationaryoperation is started and that the guidance image is faded out when thedisplay of the guidance image by the stationary operation is ended. Bydoing this, when the display of the guidance image 33 is started, theguidance image 33 displayed on the combiner 26 gradually increases inbrightness, whereas when the display of the guidance image 33 is ended,the guidance image 33 displayed on the combiner 26 gradually decreasesin brightness, so that strain on the eyes of the driver wearing thehelmet 20 can be reduced.

Moreover, while in the above-described first to third embodiments, thecolor of the arrow is changed from blue to yellow and from yellow to redas an example of the change of the display image of the direction image33 b, the present invention is not limited to these colors but differentcolors may be used. Moreover, the change display of the direction image33 b is only necessarily a display that is conspicuous to such an extentnot as to be an obstruction during traveling; for example, the flashingcondition of the arrow, the thickness and size of the arrow, acombination thereof and the like may be changed for display.

Moreover, while in the above-described first to third embodiments, thefirst reference distance is set to 500 m, the third reference distance,to 200 m, the second reference distance, to 150 m and the fourthreference distance, to 70, these numerical values are examples anddifferent numerical values may be used.

Moreover, the above-mentioned numerical values may be changed accordingto the speed of the vehicle. The above-mentioned numerical values may bechanged according to the congestion condition, the number of drivinglanes, the road width and the like. Moreover, the above-mentionednumerical values may be changed according to an intersection, an expressway, an interchange or the like.

Although it is more noticeable to the driver's eyes that the positionswhere the color of the arrow of the direction image 33 b is changed,that is, the position of 200 m of the third reference distance and theposition of 70 m of the fourth reference distance are different from theposition where the display of the distance image 33 a disappears, thatis, the position of 150 m of the second reference distance, thepositions may be the same.

While the numerical values of the first reference distance, the secondreference distance, the third reference distance, the fourth referencedistance and the fifth reference distance are automatically set, theymay be changed manually.

The numerical values of the first reference distance, the secondreference distance, the third reference distance, the fourth referencedistance and the fifth reference distance, that is, 500 m, 1 km, 2 km, 3km, 4 km and 5 km are examples, and the present invention is not limitedto these numerical values; they may be 3 km, 2 km, 1 km, 500 m or may be3 km, 2.5 km, 2 km, 1.5 km, 1 km, 500 m and 300 m.

In particular, at a location farther from the guidance point than thelocation at the first reference distance (500 m) from the guidancepoint, display is executed every predetermined distance (1 km) longerthan the first reference distance, whereas when the first referencedistance is shorter than 1 km, a different numerical value may be used.

While the guidance image 33 when the driver is at a location 500 m awayfrom the guidance point and the guidance images 33 when the driver is atlocations 5 km, 4 km, 3 km, 2 km and 1 km are of the same kind,different guidance images 33 may be displayed at the locations.

While in the first to third embodiments, ten seconds are shown as anexample of the short time during which the guidance image 33 isdisplayed at the location of the fifth reference distance, thisnumerical value is merely an example and the present invention is notlimited to this numerical value. That is, since it is necessary onlythat the driver can quickly recognize that the landmark distance isreached while driving and if the driver can recognize it, it ispreferable to quickly erase the display to increase the field of view,the display time may be shorter than ten seconds. On the contrary, sincethe driver is hindered from making a correct judgement if the displaytime is too long, it is preferable that the display time be not morethan 30 seconds at the longest.

When the navigation system 1 is activated at a location not less than 5km away from the guidance point, although no stationary operation isperformed for the guidance image 33, a different guidance image may bedisplayed, or voice information may be provided. For example, a voicesuch that “The guidance point is not less than 5 km away. Pleasecontinue driving along the traveling road.” may be outputted.

INDUSTRIAL APPLICABILITY

The present invention is usable as a display light emitting device thatemits display light to display a guidance image on a combiner mounted ona helmet.

DESCRIPTION OF REFERENCE CHARACTERS

-   -   1 Navigation system    -   10 Communication device smartphone    -   20 Helmet    -   26 Combiner    -   30 Display light emitting device    -   31 Bluetooth module (wireless communication portion)    -   32 Image control module    -   32 s Microcomputer    -   32 b Flash ROM    -   32 c GDC (image generating portion)    -   32 d LCOS (image emitting portion)    -   33 Guidance image    -   33 a Distance image    -   33 b Direction image    -   33 b 1 First route direction image    -   33 b 2 Second route direction image    -   33 b 3 Third route direction image    -   33 c Time image    -   33 d Time-of-day image    -   40 Head-up display device    -   KY1 First reference distance    -   KY2 Second reference distance    -   KY3 Third reference distance    -   KY4 Fourth reference distance    -   KY5 Fifth reference distance

1. A display light emitting device that emits display light to display aguidance image on a combiner mounted on a helmet, comprising; a wirelesscommunication portion that receives, from a communication device,guidance information including distance information indicative of adistance from a current location to a predetermined guidance point anddirection information indicative of a direction of travel at theguidance point; and an image control module having: an image generatingportion that generates a guidance image including a distance imageindicative of the distance to the guidance point based on the distanceinformation and a direction image indicative of the direction of travelat the guidance point based on the direction information; and an imageemitting portion that emits display light to display the guidance imageon the combiner, and controls operations of the image generating portionand the image emitting portion, wherein the image control moduleperforms control so that, when a condition is satisfied that thedistance indicated by the distance information is less than apredetermined first reference distance, the distance image and thedirection image are generated by the image generating portion anddisplay light to display the guidance image including the generateddistance image and direction image on the combiner is emitted from theimage emitting portion, and performs control so that from when acondition is satisfied that the distance indicated by the distanceinformation is less than a second reference distance shorter than thefirst reference distance to when the guidance point is reached, thedisplay of the distance image of the guidance image is stopped anddisplay light to continue to display the direction image is emitted. 2.The display light emitting device according to claim 1, wherein theimage control module performs control so that until a third referencedistance shorter than the first reference distance is reached, thedirection image generated by the image generating portion is a firstroute direction image, and that when a condition is satisfied that thedistance indicated by the distance information is less than the thirdreference distance, the direction image generated by the imagegenerating portion continues to be emitted from the image emittingportion to the combiner as a second route direction image formed of adisplay image different from the first route direction image.
 3. Thedisplay light emitting device according to claim 2, wherein the imagecontrol module performs control so that when a condition is satisfiedthat the distance indicated by the distance information is less than afourth reference distance shorter than the third reference distance, athird route direction image formed of a display image different from thefirst route direction image and the second route direction image isemitted from the image emitting portion to the combiner.
 4. The displaylight emitting device according to claim 3, wherein the second referencedistance is shorter than the third reference distance and is longer thanthe fourth reference distance.
 5. The display light emitting deviceaccording to claim 1, wherein the first route direction image and thesecond route direction image each include an arrow image, and the arrowimage of the first route direction image and the arrow image of thesecond route direction image are different in display condition.
 6. Thedisplay light emitting device according to claim 3, wherein the firstroute direction image, the second route direction image and the thirdroute direction image each include an arrow image, and the arrow imagesof the first route direction image, the second route direction image andthe third route direction image are different in display condition. 7.The display light emitting device according to claim 1, wherein thedistance interval from the location of the second reference distance tothe guidance point is shorter than the distance interval from thelocation of the first reference distance to the location of the secondreference distance.
 8. The display light emitting device according toclaim 1, wherein a fifth reference distance is set that is from theguidance point to a location further away from the guidance point thanthe location of the first reference distance, the fifth referencedistance is set at a plurality of points every distance interval longerthan the first reference distance, and the image control module performscontrol so that the guidance image including the distance image and thedirection image is displayed for a set predetermined period of time wheneach fifth reference distance is reached.
 9. The display light emittingdevice according to claim 8, wherein the display time of the guidanceimage displayed when the fifth reference distance is reached is not morethan 30 seconds.